1. Field of the Invention
The present invention relates to apparatus and method for suppressing vibrations for a hybrid vehicle having, for example, an engine and two motors as drive sources.
2. Description of the Related Art
A Japanese Patent Application First Publication No. 2000-217209 published on Aug. 4, 2000 exemplifies a previously proposed vibration suppression apparatus for a vehicle having a motor as the drive source. In the previously proposed vibration suppression apparatus disclosed in the above-described Japanese Patent Application First Publication, an output error between an actual plant and a plant model is inversely calculated (since torque→rotation angle is double integrals, the inverse calculation is double differentiations) and this, the result of inverse calculation, is conditioned (extraction only from a signal having a predetermined frequency band) due to the output error being caused by only an external disturbance and is additively supplies as a correction torque command. In this construction, each of the actual plant and its model is treated as one-degree-of-freedom motion (second order as a state equation).